Need Help!!!

I am hoping someone will read this and help me as obviously my Dr's can't.  I will try to start from the beginning.  about 8 weeks ago I had a sinus flair up that lead to a constant DRY cough.  The cough became so severe that my Dr.  has kept me out of work trying to figure out what is wrong.  For about 2-3 weeks she treated me with steriods and antibiotics(shots in the office sometimes).  I got no better.  The cough made extreme fatigue set in.  At no time have I had a fever.  She also put me on a nebulizer and an inhaler.  Then we went to 250/50 Advair.  The only thing that works at making the cough go away is Predisone.  However, everytime she starts weening me off the Predisone, the cough comes back and now a constant wheezing when I come off it.  She has been at witts end and has sent me to a Pulminologist.  I have had a chest xray, ct chest scan, pulminary function tests, and a bronchoscopy.  I have been told all look normal and good.  In the last 3 weeks I have started having a painful tightness in my chest.  The tightness is almost constant.  I have had 2 EKG's because of this and they are normal.  I feel like I am going crazy......depression is now my demon!!!  I know how I feel and I am not imagining it.  Could this be severe asthma?  I need any help anyone can give.  Thanks in advance.

Thanks for your reply couchtater. I do have GERD. I take Nexium which controls it most of the time. I didnt put this in my initial post but last week I had a flair up in my sleep and along with the cough I could not catch my breath and the burning from the acid in my throat almost made it impossible to swallow. Scared us so we ended up calling 911 and spending 3 hours in the ER.

No I have not had an endoscope but the pulminologist said after the Bronchoscopy that my lungs and airways all looked good....I have had GERD for quite a few years, would this just be a problem now with the shortness of breath and tightness in my chest?